Method of preparing Phenylacetaldehyde or Phenylacetic acid
1. Production of Phenylethanol from benzene and ethylene oxide
Patent No US1944959
Abstract
In a suitable container in which there has been placed 500 g of anhydrous AlCl3 there is added 800 g of benzene under stiring, 180 grams ethylene oxide in gaseous form and an equal amount of air are passed through the mixture at 45-55°C until only a small amount of AlCl3 has been left. The reaction container is constantly externally cooled with circulating water to maintain the desired temperature. The temperature is kept preferably withing the range of about substantially 45°C to about subtantially 55°C but as hereafter seen can range from -20°C upwards. The reaction product obtained is treated in the usual way with ice, seperated and vacuum distilled. In this reaction about 173 g phenylethyl alcohol and only 2 g dibenzyl were formed.
2. Ethylene Oxide
Ethanol is mixed with excess of conc sulphuric acid. Ethyl Hydrogen Sulphate is formed in the cold, but on heating to about 170°C it decomposes into ethylene and sulphuric acid.
When ethylene is mixed with air or oxygen and passed over a silver catalyst at 300°C, it is converted into ethylene oxide, a colourless liquid, BP 11C.
3. Oxidisation Of Phenylethanol (phenyl ethyl alcohol)
According to the strength of the oxidising agent used, phenylethanol can be oxidised to phenylacetaldehyde or phenylacetic acid.
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